Definition

A process (Mt)t0(M_t)_{t \geq 0} is a martingale with regard to the filtration (t)t0(\mathscr{F}_t)_{t \geq 0} if for all t0t \geq 0, MtM_t is t\mathscr{F}_t-measurable and integrable, and

𝔼[Mt|s]=Msfor all 0s<t\mathbb{E}[M_t \vert \mathscr{F}_s] = M_s \quad \text{for all } 0 \leq s < t

(conditional expectation)

See also


References

  1. https://www.cs.yale.edu/homes/aspnes/pinewiki/Martingales.html
  2. https://chewisinho.github.io/main.pdf, p. 5
  3. https://math.mit.edu/~sheffield/2019600/martingalenotes.pdf